A capsule for containing ground coffee is disclosed, the capsule comprising a frustoconical side wall (12) of truncated conical form which is closed at its narrower end by a base (16) and which has at the wider end a flange (14) which encircles the side wall (12) and extends radially outwardly. The flange (14) has a first surface to which a foil is secured to close the capsule and a further surface which faces the pressing sleeve of the extraction machine when the capsule is placed in the machine prior to extraction taking place. A grid pattern of intersecting sealing ribs is provided on the further surface which ribs stand proud of the further surface.
